Quality Assurance Handbook for Rural Roads Volume-I - pmgsy

(ii) Grading:
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Quality Assurance Handbook for Rural Roads
The stone chippings should conform to the Grading given in Table 507.4
TABLE 507.4 GRADING REQUIREMENTS FOR CHIPS FOR SURFACE DRESSING
IS Sieve Designation Cumulative percent by weight of total aggregate passing
(mm) for the following nominal sizes(mm)
13.2 9.5 6.3
19.0 100 - -
13.2 85-100 100 -
9.5 0-40 85-100 100
6.3 0-7 0-35 85-100
4.75 - 0-10 -
3.35 - - 0-35
2.36 0-2 0-2 0-10
0.60 - - 0-2
0.075 0-1.5 0-1.5 0-1.5
Minimum 65% by Passing 13.2 mm Passing 9.5 mm Passing 6.3 mm
weight of aggregate retained 3.35 mm retained 9.5 mm retained 6.3 mm
(b) Bitumen
The binder should be bituminous material, which may be as per the contract, or as decided
by the Engineer.
- Paving grade bitumen (IS 73)
- Modified bitumen (IS 15462)
- Rapid setting bitumen emulsion (IS 8887)
(c) Where aggregate fails to pass the stripping test, an approved adhesion agent may be
added to the binder, in accordance with the manufacturers instructions.
2. Horizontal Alignment
The edges of the Surface Dressing should be correct within a tolerance limit of (±) 20 mm in plain
and rolling terrain and (±) 30 mm in hilly terrain.
3. Surface Level
The tolerance in surface level of the surface dressing would be (±) 6 mm for machine laid and (±)
10 mm for manually laid surface dressing.
4. Surface Regularity
The maximum allowable difference between the pavement course and a 3 m straight edge shall
not exceed 10 mm for longitudinal profile and 12 mm for cross profile respectively.